The present disclosure relates to a reproduction device which delivers the maximum performance of a headphone device, keeps a sound pressure limitation, and supplies sound signals to the headphone device, and to a reproduction method.
In Japanese Unexamined Patent Application Publication No. 2009-232205, a technique is disclosed in which a reproduction sound pressure is not limited, but information for identifying a type of headphone device is maintained in a headphone device side so as to appropriately cancel noises in various types of headphone devices.
At present, regarding sound reproduction in a headphone device, the reproduction sound pressure is limited to a predetermined sound pressure due to hearing loss countermeasures. This regulates a maximal output voltage of an amplifier unit of the reproduction device main body and a maximal sensitivity of the headphone device (a maximal sound pressure which is obtained by performing a predetermined operation for a value obtained by measuring a headphone output when a predetermined signal is input to a headphone driver, using a so-called noise meter (which can measure a sound pressure level weighted with the frequency of the characteristic A)).
In other words, the maximal value of each of the amplifier output voltage and the headphone device sensitivity is defined, and adjustment is performed so as not to exceed the maximal value. That is to say, an amplifier with a characteristic of the “regulated maximal output amplifier output” and a headphone device with a characteristic of the “regulated maximal headphone sensitivity” are combined, and the output sound pressure is made to be within a predetermined sound pressure.
For example, in the headphone device, a resistor is connected in series to a speaker input unit thereof, thereby limiting the sound pressure.
Therefore, even if there are plural kinds of headphone devices and reproduction devices such as media players, respectively, there is no case where the headphone output sound pressure does not exceed the regulated sound pressure in any combination.